A Simulation Analysis on the Expected Horizontal Accuracy of a Bridge Stakeout

Abstract

Abstract:The positioning of an object in space, i.e. "transfer" of data from the design to the field is an extremely significant and important geodetic operation. This activity requires great and well-deserved attention, especially when it comes to sensitive structures such as bridges. The position of a stakeout point in the field depends on a variety of different influences, all determining the actual accuracy of the stakeout. The aim of this Article is to investigate the dependency of horizontal setting out of the bridge axis accuracy (abutments and piers of the bridge) from the distance between the station and the setout point, the datum of the geodetic control network, and the precision of angular and linear measurements. The authors use an innovative visualization technique for the assessment of spatial variation of the horizontal stakeout by error ellipses.

Influence of the Datum Definition on the Accuracy of Horizontal Geodetic Control Networks for Engineering Objects

“…To express the predicted uncertainty of two-dimensional position of control points, error circles (Fig. 1b) can be used with an appropriate level of confidence; this is referred to as CEP (Circular Error Probable) [6]. The radius of the standard circle which incorporates 50% of the points is calculated by Eq.…”

“…The radius of the standard circle which incorporates 50% of the points is calculated by Eq. 6: = 0.59( + ) ± 3%, for /3 < < 3 (6) An error circle with 95% confidence level is determined by Eq. 7:…”

“…Engineering construction requires a joint participation of experts from various fields, including those from the field of geodesy [1][2][3][4][5]. During construction, survey activities are conducted during different phases, starting with the production of the large-scale engineering plan (map), stakeout, to the monitoring of eventual displacement and deformations of the structure during its exploitation [6].…”

“…Global and local position accuracy of the control points is expressed through standard deviation in the direction of the coordinate axis or total positional error. The problem with this kind of accuracy prediction is that it does not provide an insight into predicted accuracy of control points within any direction -a factor which is usually critical [6]. In this article the horizontal accuracy of the control points is analyzed through absolute error ellipses and circular error probability.…”

Empowering Low-Cost Survey Instrument for the Stake-Out Measurements Using Android Application

“…The Digital Theodolites from various vendors have a standard deviation between ±10 mm up to ±16 mm 3) . The accuracy of a stake-out is indispensable to avoid overlapping in establishing infrastructure areas and public facilities 4) , even higher accuracy instrument is needed in determining geodetic network datum for bridge construction 5) . In the previous research, the accuracy of the digital leveling method, trigonometric leveling, and GPS leveling method has indicated no significant differences among them 6) .…”